1. Field of the Invention
The present invention relates to a testing module for a printed circuit board (PCB), and more particularly to a testing module for testing the strength of the welding area on the PCB.
2. Description of Related Art
Basically, there are several ways of connection between a printed circuit board (PCB) and a surface mounted device. The first method of connecting a PCB (10) and a surface mounted device (11) is by means of connecting feet, as shown in FIG. 7. It is to be noted that the connecting feet are welded on the face of the PCB (10). The second method is by solder balls (111), which are used to connect the surface mounted device (11) with a ball grid array (BGA), as shown in FIG. 8. Another commonly seen method of connecting a surface mounted device (11) to a PCB (10) is by what is called "surface welding", as shown in FIG. 9.
The reason of the surface mounted device (11) being securely mounted on the PCB (10) is after the surface mounted device (11) is secured in relation to the PCB (10), the press of a user on a random key will activate a specific circuit or a loop on the PCB (10). When the press is gone or another key is pressed to activate other circuit or loop on the PCB (10), the activation to the PCB (10) will be terminated. However, the press of a user on the key will always apply a force to the PCB (10) and will deform the PCB (10) accordingly, as shown in FIG. 12. Once the PCB (10) is permanently deformed, the connecting areas between the PCB (10) and the surface mounted device (11) will have the largest stress. As the frequency of using the PCB increases, the PCB (10) may become damaged or even break at the connecting area with the surface mounted device (11). Therefore, if the number of times that the PCB (10) can be bent is available, it is possible to know the life span of the PCB (10), and the user will know when he/she should proceed maintenance under normal operation to the PCB (10).
FIG. 10 and FIG. 11 show two kinds of conventional testing modules (20,30) for testing the strength of the welding area between a surface mounted device (11) and the PCB (10). The testing module (20,30) includes a base (21,31) having a T-shaped slot (22,32) defined therein, a pair of spaced and opposed supporting plates (23,33) movably secured on the base (21,31) by the slot (22,32) and a pressing block (24,34) reciprocally movable in relation to the pair of supporting plates (23,33). With such an arrangement, the PCB (10) is able to be placed between the pair of supporting plates (23,33) and the pressing block (24,34) controlled by a computerized device is able to apply a force to the PCB (10) placed between the pair of supporting plates (23,33). The PCB (10) after being applied a force thereon will be bent accordingly, as shown in FIG. 12. Meanwhile, a resistance indicator (not shown) is connected to the connecting area between the PCB (10) and the surface mounted device (11) to monitor the resistance therebetween. When an infinite large resistance is shown on the resistance indicator, a breakage between the PCB (10) and the surface mounted device (11) may occur. That is, a user is able to know the maximum load the connecting area between the PCB (10) and the surface mounted device (11) has and accordingly the number of times the PCB (10) can be bent.
However, using such a testing module can only test one PCB at a time, which is inefficient and time consuming.
To overcome the shortcomings, the present invention tends to provide an improved testing module for testing the strength of a welding area on a PCB to mitigate and/or obviate the aforementioned problems.